[libmultipath] don't trust the path wwid from cache if pathinfo() fails
[libmultipath] don't trust the path wwid from cache if pathinfo() fails

This kept the reduced map from loading when multipathd runs and a path
is failed or offline.

Also fix get_claimed() false positive returns by checking errno == EBUSY


unakatsuo/multipath-tools,grzn/multipath-tools-explained,unakatsuo/multipath-tools,vijaychauhan/multipath-tools,gebi/multipath-tools,grzn/multipath-tools-explained,vijaychauhan/multipath-tools,unakatsuo/multipath-tools